Fire-control apparatus



Jam 1 2 1926.

0. KRUPP FIRE CONTROL APPQRATUS med May 16. 1924 INVENTOR 80g Ifiw 10 BY I ATTORNEY I'atenteu Jan. 16, 1:140.

UNITED STATES PATENT OFFICE.

OSCAR KRUPP, 0F NASHVILLE, TENNESSEE.

FIRE-CONTROL APPARATUS.

Application filed May 16, 1924. Serial No. 713,862.

To all whom it may concern:

Be it known that I, OSCAR KRUPP, a citizen of the United States, and a resident of Nashville, county of Davidson, and State of Tennessee, have invented an Improvement in Fire-Control Apparatus, of which the following is a specification.

The invention described herein may be used by the Government, or any of its officers or employees in prosecution of work for the Government, or by any other person in the United States, without payment to me of any royalty thereon, in accordance with the act of March 3, 1883.

This invention relates to fire control apparatus for artillery.

In aiming artillery at long ranges, it is necessary to so point the gun with respect to a target that due allowance will be made for the deflection of a projectile during flight, due to the force of the wind, angular movement of the target and the drift of the projectile resulting from the rifling of the gun. The first two conditions are variable quantities at all times, while the latter is a variable quantity with each new type of gun or projectile.

The deflection boards heretofore used, necessitate modification to meet the changeable requirements of modified projectiles and guns, and are usually provided with tally dials served by an operator. In designing a simple and economically constructed deflection board capable of being used with any type of gun or projectile, it is proposed to mechanically compute, in minimum time, the amount of deflection for variations in the course and speed of the target and wind, based on the direct readings of the primary station observer, eliminate the angular travel errors due to plotting and back lash of the tally dials, and dispense with the services of the dial observer.

To these and other ends, my invention consists in the construction, arrangement, and combination of elements, described hereinafter and pointed out in the claims forming a part of this specification.

A practical embodiment of my invention is illustrated in the accompanying drawings, in which,

Fig. 1 is a plan view of my deflection board;

Fig. 2 is a fragmentary view of the azimuth slide, showing the wind curve slide and stop;

Fig. 3 is a sectional view on the line 3-3 of Fig. 1;

Fig. 4 is a sectional view on the line 4-4 of Fig. 1;

Fig. 5 is a sectional view on the line 5-5 of Fig. 1; and

Fig. 6 is a sectional view on the line 6-6 of Fig. 1.

Referring to the drawings by numerals of reference:

The deflection board comprises a base A preferably made of wood and rabbeted along its top and left edge portions to receive spaced undercut strips B and C respectively secured to the base by means of screws.

Mounted in a close sliding fit between the strips B is a slide D, which will be termed the azimuth slide and having knobs mounted on its ends to facilitate manipulation of the slide to the right or left. The slide is graduated by a double set of numbers from 3 to 9 and 8 to O to 4, this arrangement being for convenience only to reduce the total length of the slide. The numbers on the azimuth slide represent only the last or units figure, in degrees of the azimuth of the target from the directing point of the battery or other similar point represented by the gun center of the plotting board or primary station. The space between the numbers represents one degree of angular travel of the target, and is further divided into twenty divisions of .05 degrees each.

The lower of the strips B is formed with a cutout section in which is secured a strip E grooved to slidably receive a slide F formed with a stop G and having a knob H for clamping the slide in any desired position. The stop G will hereinafter be referred to as the wind curve stop.

Mounted in a close sliding fit between the strips G on the left side of the base A is the head I of a T-square, the blade forming a deflection scale K graduated from 1 to 12 representing degrees of deflection to be set on a gun sight to point the gun in the proper direction and may be conveniently subdivided as desired.

Pivotally mounted on a bracket L, secured to the lower portion of the base A is a travel arm M having a straight edge N, which is the reading edge, the opposite edge being scalloped to avoid confusion. hen in vertical position, the travel arm will intersect the deflection scale K at the graduation numbered 6, which corresponds to the normal reading of the gun sight.

A deflection chart 0, made to the scale of the board using the wind, range, and drift data from the range table of the particular gun with which the board is to be used is pasted on the base A in such a manner that the zero range and zero deflection will be directly underneath the pivot of the travel arm M. The chart is made by first plotting the drift curve P (also numbered 50) based on the range and corresponding deflection and then plotting the wind curve Q from 10 to 50 miles per hour in either direction using the drift curve P (numbered 50) as zero, the entire width of these lines being traversible by the wind curve stop G. Test points R may be included on the drift curves Q to aid in mounting the chart in proper relation to the deflection scale. A range scale S is included at the left side of the chart and covers the ranges from -0 to 27,000 yards.

The basis of plotting the chart is a horizontal scale of one inch corresponding to one-half degree of deflection and a vertical scale of one inch corresponding to five seconds time of flight of the projectile. The deflection scale K is divided on the horizontal scale of the chart 0, while the length of one degree of the azimuth scale is two and one-half times the length of one degree of the deflection scale. This relation is selected for the convenience of the board and is based on the fact that the distance from the zero range of the chart 0 to the top edge of the azimuth slide D corresponds in accordance with the vertical scale used in plotting the chart to seventyfive seconds time of flight which is two and one-half times the observing interval between azimuth readings which is assumed to be thirty seconds.

With the deflection scale K set at the corrected range on the chart 0 there will be a certain deflection for wind and drift. Assuming the wind to be moving to the right at the rate of ten miles per hour, the combined or corrected deflection will be at the intersection of the corresponding wind curve Q, and the reading edge of the reflection scale K. The travel arm M is moved on its pivot to the intersection of the wind curve and deflection scale, and the wind curve stop G moved to the left edge of the travel arm and clamped in place. The azimuth slide or scale is used to mechanically compute the deflection for a moving target knowing the angular travel for a definite period of time. Assuming the last azimuth reading to be 295.90 move the azimuth slide to the right until the graduation of the last three figures 5.90 is under the left edge of the travel arm. The next azimuth reading is taken thirty seconds later and assuming it to be 294.90, rotate the travel arm to the left by lifting it over the wind curve stop G to intersect the graduation of 4.90 on the azimuth scale at which time the combined deflection for wind, drift, and angular travel may be read on the deflection scale K at the intersection with the travel arm. In the above instance, the reading on the deflection scale K will be approximately three degrees and sixty seconds, which figure is placed on the gun sight before firing.

To set the travel arm for the next azimuth reading, return the travel arm to the wind curve stop and move the azimuth slide until the last azimuth reading intersects the travel arm. Corrections for wind or range may now be made before the next azimuth reading is received.

\Vhen this board is to be used in connection with guns or projectiles of different types, it will only be necessary to plot a new chart 0, the data for which may be obtained from the range data of the particular gun and paste the new chart on the board in proper relation to the travel arm.

The deflection obtained in the operation of this board can also be used for indirect fire by applying the deflection as a reference number to the azimuth of the target in a well-known manner.

I claim:

1. A fire control apparatus embodying a base, a graduated slide representing the angular movement of a target movably mounted on the base, a range chart including drift and wind curves stationary on the base, a graduated T-square representing the corresponding deflection to be placed on a gun sight movably mounted on the base parallel to the slide, a stop slidably carried by the base and movable across the portion of the chart including the wind and drift data, and means intersecting the T-square, chart, and slide for mechanically computing the combined deflection for wind drift and angular movement of a target.

2. A fire control apparatus embodying a base, means representing the angular travel of a target movably mounted on the base, means representing the drift and Wind deflection stationary on the base, means representing the deflection to be used on the gun sight, and means pivotally mounted on the base for intersecting all of the aforesaid means to mechanically compute the combined degree of deflection.

3. A fire control apparatus embodying a base, an azimuth scale slidably mounted horizontally of the base, a deflection scale slidable vertically of the base, a chart carried by the base, and a travel arm pivotally mounted on the base and adapted to intersect the azimuth and deflection scales to mechanically compute the degree of deflection.

4. A fire control apparatus embodying a base, means representing the angular movement of a target movably mounted on the base, means representing the corresponding deflection to be placed on the gun sight movably mounted on the base parallel to the aforesaid means, a combined range, wind, and drift chart carried by the base, said chart provided with test points, and means pivotally mounted on the base for intersecting both of the aforesaid means and the chart.

5. A fire control apparatus embodying a base, a combined range, Wind, and drift chart carried by the base, a graduated slide representing the deflection to be placed on the gun sight movable across the chart, a stop slidably carried by the base and movable across the portion of the chart including the Wind and drift data, and means pivotally mounted on the base and engageable With the stop for intersecting the de flection slide.

6. A fire control apparatus embodying a base, graduated means for recording the angular travel of a target movably mounted on the base, graduated means representing the corresponding deflection to be placed on a gun sight movably mounted on the base, a range chart, carried by the base and scaled for the time of flight of a projectile, an arm pivotally mounted on the base for intersecting both of the aforesaid means, said means being proportionately scaled on the ratio between the vertical scale from zero range to the recording means and the observing time interval between readings on the recording means.

7. A fire control apparatus embodying a base, graduated means representing the angular travel of a target movably mounted on the base graduated means representing the corresponding deflection to be placed on a gun sight movably mounted on the base, said means proportionately scaled to the first mentioned means, and means pivotally mounted on the base for intersecting both of the aforesaid means. 

